Dental articulator.



No. 682,668. Patented Sept. I7, I90].

I w. m. BRUCE.

DENTAL ARTICULATOB.

(Application filed Fab. 7, 190) (N0 Model.)

Wfnesses Ave}! (01" cams PETERS co. PHOTO-H1110 wnsmumon. n. c.

' UNITED STATES PATENT OFFICE.

WILLIAM M. BRUCE, OF TORONTO, CANADA.

.DE'NTAL ARTICULATOR.

SPECIFICATION forming part of Letters Patent No. 682,668, dated September 17, 1901.

Application filed February 7,1901. Serial No. 46,432. (No model.)

To all whom it may concern..- Be it known that I, WILLIAM M. BRUCE, L. D. S. of the city of Toronto, in the county of York, Province of Ontario,'Oanada, have in- 5 vented certain new and useful Improvements in Anatomical Dental Articulators, of which the following is a specification.

The object of my invention is to devise a dental articulator which will accurately reno produce the movements of the natural jaw; and it consists, essentially, in pivoting the upper jaw-plate on apivot movable backward .and forward in the median plane of the jawplates.

My invention also includes the means employed for cushioning the hinged upper jawplate to prevent the breakage of casts by the sudden fall of the jaw-plate after it has been swung back, the means employed to secure a .20 maximum range of vertical adjustment for the jaw-plates, and the method of making the upper jaw-frame detachable, substantially as hereinafter more specifically described and then definitely claimed.

Figure 1 is a perspective View of my articulator with the upper jaw-plate thrown back. Fig. 2 is a plan View of the upper j awplate and jaw-frame. Fig. 3 is a plan view of the articulator, showing the upper jawplate pushed back and swung to one side.

Fig. at is a perspective detail, partly broken away, illustrating the connection between the upper jaw frame and plate.

In the drawings like letters of reference in- 5 dicate corresponding parts in the different figures.

A is the artioulator-frame, comprising the cross-bar a and vertical standards I). These standards are bored to receive the posts 6 and f, connected, respectively, with the lower j awplate B and the plate I] of the upper jawframe 0. Set-screws g and h are provided, whereby the posts may be clamped within the vertical standards 6.

The upper jaw-frame 0 comprises the two plates D and E, hinged together by means of the lugs 11, through which is passed the hingepin F. Upon the upper plate D the upper jaw-plate G is supported. At the center of '50 the plate D is formed a fore-and-aft guideway H. The sides of this guideway H have V-shaped ribs 5' formed thereon to engage the similarly-recessed sides of the pivot-block I. At the rear end of the guidewayH the ribs j are omitted to permit of the pivot-blockIbeing removed. On this pivot-blockI the jawplate G is pivoted by means of the pivot-pin 70. It will be noted that this pivot-pin is located in the median plane of the upper and lower j aw-plates, and as the guideway H runs parallel to the median plane the pivot-pin 7c is always in the median plane, no matter at what point in the guideway the pivot-block may be. Hence the upper jaw-plate may be swung from side to side from a center located in the median plane, no matter whether in its normalforward position, as shown in Figs. 1, 2, and 3, orpushed back, as shown in Fig. 4. I claim this as a great point of advantage of my articulator. In the ordinary articulator, in which the upper jaw-frame has a swinging lateral motion, the swing takes place either from one side or the other and not from the center,thus in correctly representing the natural movement of the jaw when swung from side to side.

Through the ends of the upper jaw-plate I form wide slots J. Through these slots pass the large headed studs Z, their lower ends being screwed into or otherwise secured to the upper plate D of the jaw-frame. The heads of these studs serve to retain the upper jawplate in working position on the jaw-frame. At the same time the slots, being wide, permit the jaw-plate to swing freely without the sides of the slots engaging the shanks of the studs. The rear ends of the slots coming in contact with the shanks of the studs indicate the normal position of the j aw-plate, in which position it is normally retained by the spring K. This spring is secured to studs m, secured on the under side of the plate D, and its center is engaged with the end of the pivot-pin 75-, which projects through the under side of the pivot-block I. Of course othcrarrangements 5 might be used,'but that described is found very satisfactory in practice.

The upper jaw-plate is preferably formed in two parts in the ordinary manner, the two parts being connected by means of the clamping-screw L working through a slot at in the front part of the jaw-plate. At each side of the rear portion or the jaw-plate I preferably form the thumb-pieces 0, which may be engaged by the thumbs to rock the upper jawplate G upon the pivot-pin 7t.

From the construction described it will be seen that the upper jaw-plate may be swung completely back, so as to lie on the table when desired, making it very convenient to work at a cast on either jaw-plate from all sides, and may quicklybe detached from the articulator by removing the hinge pin F. When the parts are assembled again and the hinge-pin placed in position, itwill be found that the two jaw-frames are again brought into exactly the same relative position, which is not the case if the jaw-frame and the casts which may be attached to it are removed by unscrewingthe clamp-nut L, as is usually necessary.

Screwed through the cross-bar a of the articulator-frame is a leveling-screw M, provided with the clamp-nutp. Upon the upper end of this leveling-screw I screw the nut q. This nut is preferably formed with a sleeve, as shown, around which is secured a short section of coil-spring 1'. By adjusting the nut upon the leveling-screw a greater or lesser portion of this coil-spring may be caused to project above the end of the leveling-screw. The leveling-screw is of course used in the ordinary way to regulate the downward movements of the upper jaw-plate. The coil-spring forms aspring-cushion, which cases the shock caused if the upper jaw-plate be allowed to fall down when plaster casts are in position on the articulator. The danger of breaking casts in this manner is thus largely obviated. The spring-cushion being vertically adjustable permits of the amount of the spring-cushioning being accurately regulated to suit the operators requirements. The spring which thus automatically cushions the fall of the upper jaw-plate serves also another purpose. When testing casts as to the correct position of the teeth, the casts are opened and. closed as in the natural action of biting. After the casts have been brought together by the operator the spring r separates the jaw-plates as soon as the operator releases them and so separates the casts. This is a great convenience, as the operator is saved the trouble of making the double movement. As the spring is connected to the leveling-screw, it follows the latter as it is adjusted to suit the adjustment of the upper jaw-plate by means of the postsf.

From the above'description it will be seen that I have devised an articulator which will completely reproduce all the movements of the natural jaw-the opening and closing movement, the backward and forward movement, and the lateral swing from a point located in the median plane of the aws. I have provided an articulator in which the maximum range of vertical adjustment for the jaw-plates is secured owing to the independent vertical adjustment provided for the posts 6 and f. The construction of the articulator-frame is such as to leave almost entirely unobstructed the view from the rear of the articulator through to the inner sides of any casts connected to the jaw-plates. Detachability of the upper jaw-plate without destroying the adjustment is provided for and the possibility of breakage by the sudden fall of the upper jaw-plate is obviated.

What I claim as my invention is 1. In an articulator provided with upper and lower jaw-plates, a pivot located in the median planeof the jaw-plates, said pivot being mounted in a support adapted to move backward and forward, combined with the upper jaw-plate adapted to swing 011 said pivot and extend laterally on each side of the same whereby the sides of the said upper jaw-plate swing backward and forward when the front of the jaw-plate swings laterally and means for limiting the backward and forward swing of the sides of the said jawplate, substantially as described.

2. In an articulator provided with upper and lower jaw-plates, a pivot located in the median plane of the jaw-plates and so mounted that it may. be moved backward and forward in com bination with the upper jaw-plate adapted to swing on said pivot; and a spring tending to maintain the said pivot in its forward position, substantially as described.

3. In an articulator provided with upper and lower jaw-plates, the combination with one of the jaw-plates adapted to have an end wise motion and also a lateral swing from a movable center located in the median plane of the jaw-plates; of a spring having its ends attached to the upper jaw-frame and intermediate its ends bearing directly upon the pivot 01' the upper jaw-plate adapted to return the said jaw-plate to its normal position, substantially as described.

4:. In an articulator, upper and lower jawplates adapted to have an endwise motion relative to one another and also a simultaneous lateral swing from a movable center located in the median plane of the jaw-plates, substantially as described.

In an articulator upper and lower jawplates adapted to have an endwise motion relative to one another and alsoa simultaneous lateral swing from a movable center located in the median plane of the jaw-plates, in combination with a spring adapted to return the jaw-plates to their normal position, and a cushioning device for the upper jawplate, substantially as described.

6. In an articulator, the articulator-frame comprising a cross-bar and vertical standards at each side, each having two vertical holes bored therein, in combination with a lower jaw-plate, provided with two vertical posts adapted to fit two of the said holes; an upper jaw-plate connected with two vertical posts adapted to lit the other two holes in the standards; and set-screws adapted to clamp the said posts, substantially as described.

7. In an articulator, an articulator-frame, in combination with an upper jaw-plate hav- IIO ing a hinged and vertically-adjustable con-- nection therewith; a leveling-screw screwed through the frame and adapted to engage the under side of the upper jaw-plate; a nut screwed on the upper end of the levelingscrew; and a spring-cushion carried by the said nut, substantially as described.

8. In an articulator, an articulator-frame, in combination with an upper jaw frame formed in two parts detachably hinged together the lower part being vertically adj 11stable on the articulator-frame; and an upper jaw-plate connected with the upper part of the said upper jaw-frame, substantially as described.

9. In an articulator, an upper jaw-frame connected with the articulator-frame and having a central fore-and-aft guideway formed therein, in combination with a pivot-block adapted to slide in the said guideway; and an upper jaw-plate mounted to swing laterally upon a pivot carried by said block and adapted for simultaneous backward-and-forward opening and closing and lateral movements, substantially as described.

10. In an articulator, an upper jaw-frame connected with the articulator-frame and having a central fore-and-aft guideway formed therein, in combination with a pivot-block adapted to slide in the said guideway; an upper jaw-plate pivoted thereon; and headed studs connected to the upper jaw-frame and passing through wide slots in the jaw-plate, substantially as described.

11. In an articulator, an upper jaw-frame connected with the articulator-frame and hav ing a central fore-and-aft guideway formed therein, in combination with-a pivot-block adapted to slide in the said guideway; an upper jaw-plate pivoted thereon; headed studs connected to the upper jaw-frame and passing through wide slots in the jaw-plate; and a spring engaging the pivot-block and thenpper jaw-frame and tending to maintain the therein, in combination with a pivot-block adapted to slide in the said guideway; an upper jaw-plate pivoted thereon to swing laterally simultaneously with its sliding movement 5 means limiting the swinging movement of the jaw-plate and a spring normally maintaining the jaw-plate in its forward position, substantially as described.

13. In an articulator, an articulator-frame, in combination with an upper jaw -frame formed in two parts hinged together, the lower part being connected to the articulator-frame; and an upper jaw-plate connected with the upper part of the said upper jaw-frame by a vertically-disposed pivot in the medianplane of the jaw-plates, substantially as described.

14. In an articulator provided with upper and lower jaw-plates, a pivot located in the median plane of the jaw-plates and mounted for movement backward and forward and in terrupted guideways for said pivot whereby it may be removed when desired, combined with an upper jaw-plate mounted to swing laterally on said pivot, and a spring acting directly upon said pivot, substantially as de-' scribed.

15. An articulator provided with upper and lower jaw-plates, one of which is adapted to have a bodily endwise motion from a movable center located in the median plane of the jaw plates, a guide for said center having portions adapted to permit of the bodily removal of said center, and a spring acting directly upon said center, as and for the purpose specified.

Toronto, January 24., 1901.

WILLIAM M. BRUCE.

In presence ofa J. Enw. MAYBEE, A. J. CoLBoURNn. 

